hishel 1.1.2

Elegant HTTP Caching for Python

Hishel

Elegant HTTP Caching for Python

---

Hishel (հիշել, to remember in Armenian) is a modern HTTP caching library for Python that implements RFC 9111 specifications. It provides seamless caching integration for popular HTTP clients with minimal code changes.

✨ Features

• 🎯 RFC 9111 Compliant - Fully compliant with the latest HTTP caching specification
• 🔌 Easy Integration - Drop-in support for HTTPX, Requests, ASGI, FastAPI, and BlackSheep
• 💾 Flexible Storage - SQLite backend with more coming soon
• ⚡ High Performance - Efficient caching with minimal overhead
• 🔄 Async & Sync - Full support for both synchronous and asynchronous workflows
• 🎨 Type Safe - Fully typed with comprehensive type hints
• 🧪 Well Tested - Extensive test coverage and battle-tested
• 🎛️ Configurable - Fine-grained control over caching behavior with flexible policies
• 💨 Memory Efficient - Streaming support prevents loading large payloads into memory
• 🌐 Universal - Works with any ASGI application (Starlette, Litestar, BlackSheep, etc.)
• 🎯 GraphQL Support - Cache GraphQL queries with body-sensitive content caching

📦 Installation

pip install hishel

Optional Dependencies

Install with specific integration support:

pip install hishel[httpx]      # For HTTPX support
pip install hishel[requests]   # For Requests support
pip install hishel[fastapi]    # For FastAPI support (includes ASGI)

Or install multiple:

pip install hishel[httpx,requests,fastapi]

[!NOTE] ASGI middleware has no extra dependencies - it's included in the base installation.

🚀 Quick Start

With HTTPX

Synchronous:

from hishel.httpx import SyncCacheClient

client = SyncCacheClient()

# First request - fetches from origin
response = client.get("https://api.example.com/data")
print(response.extensions["hishel_from_cache"])  # False

# Second request - served from cache
response = client.get("https://api.example.com/data")
print(response.extensions["hishel_from_cache"])  # True

Asynchronous:

from hishel.httpx import AsyncCacheClient

async with AsyncCacheClient() as client:
    # First request - fetches from origin
    response = await client.get("https://api.example.com/data")
    print(response.extensions["hishel_from_cache"])  # False
    
    # Second request - served from cache
    response = await client.get("https://api.example.com/data")
    print(response.extensions["hishel_from_cache"])  # True

With Requests

import requests
from hishel.requests import CacheAdapter

session = requests.Session()
session.mount("https://", CacheAdapter())
session.mount("http://", CacheAdapter())

# First request - fetches from origin
response = session.get("https://api.example.com/data")

# Second request - served from cache
response = session.get("https://api.example.com/data")
print(response.headers.get("X-Hishel-From-Cache"))  # "True"

With ASGI Applications

Add caching middleware to any ASGI application:

from hishel.asgi import ASGICacheMiddleware

# Wrap your ASGI app
app = ASGICacheMiddleware(app)

# Or configure with options
from hishel import AsyncSqliteStorage, CacheOptions, SpecificationPolicy

app = ASGICacheMiddleware(
    app,
    storage=AsyncSqliteStorage(),
    policy=SpecificationPolicy(
      cache_options=CacheOptions(shared=True)
    ),
)

With FastAPI

Add Cache-Control headers using the cache() dependency:

from fastapi import FastAPI
from hishel.fastapi import cache

app = FastAPI()

@app.get("/api/data", dependencies=[cache(max_age=300, public=True)])
async def get_data():
    # Cache-Control: public, max-age=300
    return {"data": "cached for 5 minutes"}
  
# Optionally wrap with ASGI middleware for local caching according to specified rules
from hishel.asgi import ASGICacheMiddleware
from hishel import AsyncSqliteStorage

app = ASGICacheMiddleware(app, storage=AsyncSqliteStorage())

With BlackSheep

Use BlackSheep's native cache_control decorator with Hishel's ASGI middleware:

from blacksheep import Application, get
from blacksheep.server.headers.cache import cache_control

app = Application()

@get("/api/data")
@cache_control(max_age=300, public=True)
async def get_data():
    # Cache-Control: public, max-age=300
    return {"data": "cached for 5 minutes"}

🎛️ Advanced Configuration

Caching Policies

Hishel supports two types of caching policies:

SpecificationPolicy - RFC 9111 compliant HTTP caching (default):

from hishel import CacheOptions, SpecificationPolicy
from hishel.httpx import SyncCacheClient

client = SyncCacheClient(
    policy=SpecificationPolicy(
        cache_options=CacheOptions(
            shared=False,                              # Use as private cache (browser-like)
            supported_methods=["GET", "HEAD", "POST"], # Cache GET, HEAD, and POST
            allow_stale=True                           # Allow serving stale responses
        )
    )
)

FilterPolicy - Custom filtering logic for fine-grained control:

from hishel import FilterPolicy, BaseFilter, Request
from hishel.httpx import AsyncCacheClient

class CacheOnlyAPIRequests(BaseFilter[Request]):
    def needs_body(self) -> bool:
        return False
    
    def apply(self, item: Request, body: bytes | None) -> bool:
        return "/api/" in str(item.url)

client = AsyncCacheClient(
    policy=FilterPolicy(
        request_filters=[CacheOnlyAPIRequests()]
    )
)

Learn more about policies →

Custom Storage Backend

from hishel import SyncSqliteStorage
from hishel.httpx import SyncCacheClient

storage = SyncSqliteStorage(
    database_path="my_cache.db",
    default_ttl=7200.0,           # Cache entries expire after 2 hours
    refresh_ttl_on_access=True    # Reset TTL when accessing cached entries
)

client = SyncCacheClient(storage=storage)

GraphQL and Body-Sensitive Caching

Cache GraphQL queries and other POST requests by including the request body in the cache key.

Using per-request header:

from hishel import FilterPolicy
from hishel.httpx import SyncCacheClient

client = SyncCacheClient(
    policy=FilterPolicy()
)

# Cache GraphQL queries - different queries get different cache entries
graphql_query = """
    query GetUser($id: ID!) {
        user(id: $id) {
            name
            email
        }
    }
"""

response = client.post(
    "https://api.example.com/graphql",
    json={"query": graphql_query, "variables": {"id": "123"}},
    headers={"X-Hishel-Body-Key": "true"}  # Enable body-based caching
)

# Different query will be cached separately
response = client.post(
    "https://api.example.com/graphql",
    json={"query": graphql_query, "variables": {"id": "456"}},
    headers={"X-Hishel-Body-Key": "true"}
)

Using global configuration:

from hishel.httpx import SyncCacheClient
from hishel import FilterPolicy

# Enable body-based caching for all requests
client = SyncCacheClient(policy=FilterPolicy(use_body_key=True))

# All POST requests automatically include body in cache key
response = client.post(
    "https://api.example.com/graphql",
    json={"query": graphql_query, "variables": {"id": "123"}}
)

🏗️ Architecture

Hishel uses a sans-I/O state machine architecture that separates HTTP caching logic from I/O operations:

• ✅ Correct - Fully RFC 9111 compliant
• ✅ Testable - Easy to test without network dependencies
• ✅ Flexible - Works with any HTTP client or server
• ✅ Type Safe - Clear state transitions with full type hints

🔮 Roadmap

We're actively working on:

• 🎯 Performance optimizations
• 🎯 More integrations
• 🎯 Partial responses support

📚 Documentation

Comprehensive documentation is available at https://hishel.com/dev

• Getting Started
• HTTPX Integration
• Requests Integration
• ASGI Integration
• FastAPI Integration
• BlackSheep Integration
• GraphQL Integration
• Storage Backends
• Request/Response Metadata
• RFC 9111 Specification

🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request. For major changes, please open an issue first to discuss what you would like to change.

See our Contributing Guide for more details.

📄 License

This project is licensed under the BSD-3-Clause License - see the LICENSE file for details.

💖 Support

If you find Hishel useful, please consider:

• ⭐ Starring the repository
• 🐛 Reporting bugs and issues
• 💡 Suggesting new features
• 📖 Improving documentation
• ☕ Buying me a coffee

🙏 Acknowledgments

Hishel is inspired by and builds upon the excellent work in the Python HTTP ecosystem, particularly:

• HTTPX - A next-generation HTTP client for Python
• Requests - The classic HTTP library for Python
• RFC 9111 - HTTP Caching specification

---

Made with ❤️ by Kar Petrosyan

What's Changed in 1.1.2

• fix: respect shared option when excluding unstorable headers by @karpetrosyan
• fix: remove s-maxage consideration for private caches by @karpetrosyan
• fix: respect shared option when excluding unstorable headers by @jlopex in #401
• fix: remove s-maxage consideration for private caches by @jlopex in #400
• fix: ensure 304 responses don't leak by @karpetrosyan

New Contributors

• @jlopex made their first contribution in #401

Full Changelog: https://github.com/karpetrosyan/hishel/compare/1.1.1...1.1.2

What's Changed in 1.1.1

• Revert "Revert "chore(deps): bump actions/upload-artifact from 4 to 5 "" by @karpetrosyan
• Revert "chore(deps): bump actions/download-artifact from 4 to 6 " by @karpetrosyan
• Revert "chore(deps): bump actions/upload-artifact from 4 to 5 " by @karpetrosyan
• update uv.lock by @karpetrosyan
• Version 1.1.1 by @karpetrosyan

Full Changelog: https://github.com/karpetrosyan/hishel/compare/1.1.0...1.1.1

What's Changed in 1.1.0

• Version 1.1.0 by @karpetrosyan
• fix: pass any response with non-expected status code on revalidation to client by @karpetrosyan
• fix: pass any response with non-expected status code on revalidation to client by @karpetrosyan
• feat: allow setting storage base with via database_path for sqlite storage by @karpetrosyan
• fix in memory example by @karpetrosyan
• chore: add in memory example by @karpetrosyan

Full Changelog: https://github.com/karpetrosyan/hishel/compare/1.0.0...1.1.0

What's Changed in 1.0.0

• Version 1.0.0 by @karpetrosyan
• chore(docs): add examples, improve docs by @karpetrosyan

Full Changelog: https://github.com/karpetrosyan/hishel/compare/1.0.0b1...1.0.0

What's Changed in 1.0.0b1

• Version 1.0.0b1 by @karpetrosyan
• improve docs by @karpetrosyan
• fix: filter out Transfer-Encoding header for asgi responses by @karpetrosyan
• fix body sensitive docs by @karpetrosyan
• refactor: add policies by @karpetrosyan
• chore(docs): add graphql docs by @karpetrosyan
• feat: add global use_body_key setting by @karpetrosyan
• chore(docs): improve sans-io diagram colors by @karpetrosyan
• fix: body-sensitive responses caching by @karpetrosyan
• mention body sensitive content caching by @karpetrosyan
• clean up roadmap by @karpetrosyan

Full Changelog: https://github.com/karpetrosyan/hishel/compare/1.0.0.dev3...1.0.0b1

What's Changed in 1.0.0.dev3

• Version 1.0.0.dev3 by @karpetrosyan
• fix ci by @karpetrosyan
• fix: add date header for proper age calculation by @karpetrosyan
• rename some methods by @karpetrosyan
• refactor: automatically generate httpx sync integration from async by @karpetrosyan
• change pairs to entries in some places by @karpetrosyan
• fix lint format by @karpetrosyan
• refactor: replace pairs with entries, simplify storage API by @karpetrosyan
• better docs by @karpetrosyan
• better custom integrations docs by @karpetrosyan
• more private by @karpetrosyan
• fix lint, make things private by @karpetrosyan
• dont fail if unasync rule was not used by @karpetrosyan
• chore: more robust compressed response caching by @karpetrosyan
• chore(docs): add custom integrations docs by @karpetrosyan
• feat: add logging for asgi by @karpetrosyan
• fix: handle httpx iterable usage instead of iterator correctly by @karpetrosyan
• feat: add blacksheep integration examples by @karpetrosyan
• Change note syntax for ASGI middleware by @karpetrosyan
• fix lint by @karpetrosyan
• feat: add integrations with fastapi and asgi by @karpetrosyan
• fix readme by @karpetrosyan
• add icon for introduction page by @karpetrosyan
• fix test by @karpetrosyan
• properly close resource by @karpetrosyan
• fix: fix compressed data caching for requests by @karpetrosyan
• fix: raise on consumed httpx streams, which we can't store as is (it's already decoded) by @karpetrosyan
• chore(docs): simplify metadata docs by @karpetrosyan
• fix: add missing permissions into publish.yml by @karpetrosyan

Full Changelog: https://github.com/karpetrosyan/hishel/compare/1.0.0.dev2...1.0.0.dev3

What's Changed in 1.0.0.dev2

• Version 1.0.0.dev2 by @karpetrosyan
• unasync by @karpetrosyan
• chore: fix time travel date, explicitly specify the timezone by @karpetrosyan
• fix: don't raise an error on 3xx during revalidation by @karpetrosyan
• chore: add import without extras check in ci by @karpetrosyan
• chore(internal): remove redundant utils and tests by @karpetrosyan
• feat: add hishel_created_at response metadata by @karpetrosyan
• fix: fix check for storing auth requests by @karpetrosyan
• better git-cliff by @karpetrosyan

Full Changelog: https://github.com/karpetrosyan/hishel/compare/1.0.0.dev1...1.0.0.dev2

What's Changed in 1.0.0.dev1

• Version 1.0.0.dev1 by @karpetrosyan
• fix changelog + uv lock by @karpetrosyan
• fix linting by @karpetrosyan
• chore(internal): remove some redundant utils methods by @karpetrosyan
• fix mike deploy by @karpetrosyan

Full Changelog: https://github.com/karpetrosyan/hishel/compare/1.0.0.dev0...1.0.0.dev1

What's Changed in 1.0.0.dev0

• fix publish.yml by @karpetrosyan
• fix format by @karpetrosyan
• prepare 1.0.0.dev0 release by @karpetrosyan
• improve CacheOptions docs by @karpetrosyan
• don't make release version latest by default by @karpetrosyan
• fix changelog by @karpetrosyan
• fix action permissions by @karpetrosyan
• improve docs introduction by @karpetrosyan
• better docs publishing, better project description by @karpetrosyan
• fix docs publishing by @karpetrosyan
• fix docs deploying by @karpetrosyan
• chore(docs): improve docs versioning, deploy dev doc on ci by @karpetrosyan
• fix unasync by @karpetrosyan
• fix unasync by @karpetrosyan
• fix unasync by @karpetrosyan
• Version 1.0.0.dev0 by @karpetrosyan
• chore(docs): use mike powered versioning by @karpetrosyan
• fix changelog by @karpetrosyan

Full Changelog: https://github.com/karpetrosyan/hishel/compare/0.1.5...1.0.0.dev0

What's Changed in 0.1.5

• Version 0.1.5 by @karpetrosyan in #385
• feat(perf): increase requests buffer size to 128KB, disable charset detection by @karpetrosyan
• feat: add close method to storages API by @karpetrosyan in #384
• fix headers by @karpetrosyan
• fix lint by @karpetrosyan
• ruff format by @karpetrosyan
• feat: better cache-control parsing by @karpetrosyan
• feat(perf): set chunk size to 128KB for httpx to reduce SQLite read/writes by @karpetrosyan
• fix(docs): fix some line breaks by @karpetrosyan
• chore: remove some redundant files from repo by @karpetrosyan

Full Changelog: https://github.com/karpetrosyan/hishel/compare/0.1.4...0.1.5

What's Changed in 0.1.4

• Version 0.1.4 by @karpetrosyan in #381
• fix lint by @karpetrosyan
• more docs! by @karpetrosyan
• ensure connection is not stored by @karpetrosyan
• fix annotations by @karpetrosyan
• fix typing by @karpetrosyan
• format by @karpetrosyan
• more docs! more tests! by @karpetrosyan
• lot of fixes by @karpetrosyan
• remove redundant files by @karpetrosyan
• remove docs footer by @karpetrosyan
• fix: fix beta imports by @karpetrosyan
• uv lock by @karpetrosyan
• fix: create an sqlite file in a cache folder by @karpetrosyan
• better unasync by @karpetrosyan
• feat: better async implemetation for sqlite storage by @karpetrosyan
• feat: get rid of some locks from sqlite storage by @karpetrosyan
• chore(tests): move some tests to beta by @karpetrosyan
• fix tests by @karpetrosyan
• fix tests by @karpetrosyan
• fix lint by @karpetrosyan
• chore(tests): add sqlite tests for new storage by @karpetrosyan
• feat: add sqlite storage for beta storages by @karpetrosyan
• Adding .venv to .gitignore by @jamesbraza in #379
• Revert "add ethical ads" by @karpetrosyan
• add ethical ads by @karpetrosyan
• feat: allow already consumed streams with CacheTransport by @jamesbraza in #377
• chore(ci): fix lint script by @GugNersesyan in #375
• chore(internal): temporary remove python3.14 from CI by @karpetrosyan
• chore(internal): remove src folder by @karpetrosyan in #373
• New storage API by @karpetrosyan in #359
• chore: improve CI by @karpetrosyan in #369
• feat: add support for a sans-IO API by @karpetrosyan in #366
• Enhance documentation with donation link by @karpetrosyan in #368
• Update README to include donation link by @karpetrosyan in #367
• Added Metadata to public API by @jamesbraza in #363
• Bump the python-packages group with 10 updates by @dependabot[bot] in #354
• skip anysqlite, yaml and redis tests if optional deps are missing by @mmdbalkhi in #348
• Don't bomb if directory creation races by @AstraLuma in #353
• Cleanup module imports by @deathaxe in #351

New Contributors

• @jamesbraza made their first contribution in #379
• @GugNersesyan made their first contribution in #375
• @mmdbalkhi made their first contribution in #348
• @AstraLuma made their first contribution in #353
• @deathaxe made their first contribution in #351

Full Changelog: https://github.com/karpetrosyan/hishel/compare/0.1.3...0.1.4